The parent patent application that has been referenced above relates to a fuel rail that contains a novel fuel injector configuration which allows for certain reductions in the size of the envelope that is occupied by the fuel rail assembly on an internal combustion engine, particularly reductions in the extent to which the fuel injectors project transversely of the fuel rail. The exemplary fuel rail assembly comprises a circular cylindrical-walled tube within which essentially the entirety of each fuel injector is disposed so that the transverse dimension of the fuel rail assembly at the location of a fuel injector is essentially that of the O.D. of the tube. The tube may be either a separate tube that is itself ultimately attached to the engine, or means defining a hole in the engine manifold. The fuel injectors are mounted on a carrier to form a sub-assembly that is assembled into the tube by endwise insertion. The electrical leads for the fuel injectors run along the carrier to a receptacle that is at one lengthwise end of the completed fuel rail assembly. Pressurized liquid fuel fills the interior of fuel rail tube to immerse the fuel injectors. The injectors' nozzles, from which fuel is injected, are seated in a sealed manner in holes in the sidewall of the tube.
The fuel injectors themselves are unique. Rather than having a solenoid, an armature, a needle, and a seat coaxially arranged along the length of the fuel injector, as in conventional fuel injectors, each fuel injector has a magnetic circuit that encircles a spherical valve element. This sphere is resiliently urged by a cantilever spring blade toward closure of an outlet hole that is circumscribed by a frusto-conical seat. The sphere-encircling magnetic circuit may be considered to comprise four sides. The armature and the solenoid are disposed at two opposite sides. The stator has a U-shape whose base passes through the solenoid and whose legs form the remaining two sides. The armature is a bar of magnetically permeable material whose midpoint acts on the sphere. When the solenoid is not energized, working gaps exist between the ends of the bar and the distal ends of the stator's legs, and when the solenoid is energized, the magnetic flux attracts the bar to reduce these working gaps. As a result, the bar pushes the sphere out of concentricity with the seat to cause the outlet hole to open and pass the pressurized liquid fuel for injection. When the solenoid is de-energized, the cantilever spring pushes the sphere back to concentricity with the seat, and the resultant closure of the outlet hole terminates the injection. The fuel injector of the invention is well-suited for miniaturization to fit within a fuel rail and is an efficient and economical use of parts and materials.
The invention of the referenced division and continuation-in-part patent application relates to features of the fuel rail assembly and its method of manufacture. The fuel rail assembly comprises an elongated carrier that contains spaced apart cavities in which the fuel injectors are respectively disposed. The carrier also contains electric circuitry for operating the fuel injectors, and includes electrical terminals for making electrical circuit connection to a remotely located engine management computer which delivers principal command signals to the fuel rail assembly for operating the fuel injectors. The carrier-mounted electric circuitry also includes its own microprocessor, a calibration PROM (programmable read only memory, fuel injector drivers, and related auxiliary electronic circuit devices. These further electronic circuit components provide for the fuel rail assembly to be electronically calibrated for dynamic flow throughout the entire dynamic operating range. The inclusion of such electronic circuitry in the fuel rail assembly confers a number of substantial benefits, as described in detail in the referenced patent application. It becomes possible to fabricate a common fuel rail assembly that can be electronically customized and adapted to accommodate a multitude of varying uses and that will be properly calibrated for dynamic flow over its full range.
The invention that is the subject of the present patent application relates to an end closure and electrical connector for fuel rails of the type disclosed in the referenced patent applications, especially the later application.
In the fuel rail of the referenced parent application, the electrical connector is provided at one end of the carrier. Lead wires extend along the carrier from the fuel injectors to the electrical connector. With the carrier having been assembled into the main longitudinal hole in the fuel rail tube, the connector will be disposed at an open end of that tube which is subsequently closed by a suitably shaped closure that allows the connector to be exposed to the exterior of the fuel rail and to be mated with a complementary connector of a wiring harness that leads to the engine management computer which delivers signals to the fuel rail assembly for operating the fuel injectors.
The present invention proposes a combined fuel rail end closure and electrical connector which will provide certain advantages and benefits for such a fuel rail assembly. One of the chief benefits is that sealing of the end closure and electrical connector can be accomplished at a single pair of confronting circular surfaces, one surface being on the tube and the other on the end closure and electrical connector. For example, the surfaces may be telescopically engaged, and an O-ring seal provided between them. Because the end closure and electrical connector has not yet been assembled to the carrier at the time of assembly of the carrier to the tube, the possibility that it will impede or complicate the process of assembling the carrier to the tube is foreclosed.
Further features, advantages, and benefits of the invention, along with those already mentioned, will be seen in the ensuing description and claims, which are accompanied by drawings. The drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.